gist.js

  // "lo1":0.0,
  // "la1":90.0,
  // "lo2":359.75003,
  // "la2":-90.0,
  // "dx":0.25,
  // "dy":0.25

  var features = [];
  var lat = 90;
  var lon = 0;

  _.each(data, function(d, i) {
  
    //just to keep it small ish, only add when in lat range 
    if ( lat < 48 && lat > 25) {
      var obj = {};
      obj.type = 'Feature';
      obj.properties = {'value': Math.round(9/5*(d - 273) + 32)};
      obj.geometry = {};
      obj.geometry.type = "Point";
      obj.geometry.coordinates = [lon, lat];
      features.push(obj);
    }

    //each point iterate lon 0.25 deg
    lon = lon+0.25;

    //at -180, start over
    if ( lon > 180 ) {
      lon = -180;
    }

    //at 0 step down lat
    if ( lon === 0 ) {
      lat = lat - 0.25;
    }

  });